Field of the Invention
The present invention relates generally to an implantable stimulator, and more particularly, to a sub-cranial vibratory stimulator.
Related Art
Hearing loss, which may be due to many different causes, is generally of two types, conductive and/or sensorineural. Conductive hearing loss occurs when the normal mechanical pathways of the outer and/or middle ear are impeded, for example, by damage to the ossicular chain or ear canal. Sensorineural hearing loss occurs when there is damage to the inner ear, or to the nerve pathways from the inner ear to the brain.
Individuals suffering from conductive hearing loss typically receive an acoustic hearing aid. Hearing aids rely on principles of air conduction to transmit acoustic signals to the cochlea. Typically, a hearing aid is positioned in the ear canal or on the outer ear to amplify received sound. This amplified sound is delivered to the cochlea through the normal middle ear mechanisms resulting in the increased perception of sound by the recipient.
In contrast to acoustic hearing aids, certain types of auditory prostheses, commonly referred to as bone conduction devices, convert a received sound into vibrations. The vibrations are transferred through a recipient's skull bone to the cochlea, causing generation of nerve impulses, which result in the perception of the received sound. Bone conduction devices may be used to treat a variety of types of hearing loss and may be suitable for individuals who cannot derive sufficient benefit from acoustic hearing aids, cochlear implants, etc., or for individuals who suffer from stuttering problems.